Research: Asthma affects over 300 million individuals with up to an estimated 10% suffering from ?treatment- resistant? asthma, for whom alternative strategies are needed. Airway smooth muscle (ASM) undergoes significant changes in asthma that increase bronchoconstriction and impair lung function. Treatments and therapies that target ASM specifically may therefore offer an alternative approach to controlling asthma, but progress is impeded by the difficulty in assessing ASM in a clinical setting. Recently we have demonstrated an imaging platform based on polarization-sensitive optical coherence tomography (PS-OCT) capable of assessing ASM distributions in vivo by exploiting the form birefringence of smooth muscle. In this proposal we are aiming to develop, validate, and implement in a pilot clinical study an extension to this technology that can be used to assess ASM function. This technology has the potential to advance not only asthma research, but research of many diseases and disorders involving smooth muscle in a number of organ systems. Candidate: David Adams, PhD is an Instructor in Medicine on the tenure track at Harvard Medical School. His long-term career goal is to become an independent translational researcher in functional imaging, focusing primarily on ASM and asthma. He has a strong background in physics, with emphasis on optics and signal processing. Since beginning postdoctoral research at Massachusetts General Hospital (MGH), he has worked on developing novel data processing techniques to maximize the utilization of data obtained with OCT imaging. The focus of this being the assessment of ASM with PS-OCT. This research will greatly benefit him in his transition to independent translational research by providing him with invaluable training in lung physiology and clinical research. Environment: Dr. Adams will train in an exceptional environment at MGH, with an abundance of resources available to help him conduct his research. His mentoring team is comprised of internationally recognized leaders in their fields: Dr. Melissa Suter, primary mentor, is a luminary in the field of translational OCT research, having been directly involved in seminal studies aimed at translating OCT imaging to the clinic. Dr. Brett Bouma, co-primary mentor, of the Wellman Center for Photomedicine at MGH is one of the key progenitors of OCT technology and translational OCT. Dr. Kenneth Lutchen, a secondary mentor, of Boston University is a pioneer in the development of experiments aimed at investigating lung physiology, and specifically ASM. Dr. Benjamin Medoff, also a secondary mentor, is chief of the Division of Pulmonary and Critical Care at MGH and a leading figure in clinical asthma research. In addition to this impressive mentoring team, Dr. Adams also has immediate access to the tremendous intellectual and collaborative opportunities available at MGH and Harvard.